Dye carrier



United States Patent This invention relates to dye carriers comprising phenylphenol and to processes utilizing such carriers. In particular, it relates to the use of a combination of sodium dodecyldiphenyl oxide disulfonate and phenylphenol as a dye carrier.

It is well known to use phenylphenol as a dye carrier,

especially in the dyeing of synthetic polyester fibers. One dilficulty in such practice, however, arises from the fact that the phenol is substantially insoluble in neutral or acid solutions, thus requiring the use of strong alkali to render it soluble. Such alkali is objectionable because of its added cost, its harmful effect on the fiber and its inhibitory effect on the dyeing itself. Many dyes are most effective and have the greatest aflinity for fibers when in neutral of acid solutions.

Accordingly, it is an object of this invention to provide dye carriers utilizing the useful properties of phenylphenol but avoiding the excessively high pH heretofore considered necessary for its use. Other objects will ap pear hereinafiter.

According to the invention, the effectiveness of phenylphenol as a dye carrier is enhanced and the pH required for its effective use is lowered by using it in conjunction with sodium dodecyldiphenyl oxide disulfonate. The latter compound is sold commercially by The Dow Chemical Company under the tradename Dowfax 2A1.

In a preferred mode of practicing the invention, the phenylphenol is dissolved or dispersed in a concentrated aqueous solution of the Dowfax. The concentrate thus formed is added to the dye bath in the desired amount and quickly dissolves or disperses therein to form a homogenous bath composition.

The beneficial eifeot of using the Dowfax in conjunction with phenylphenol as a dye carrier is obtained in any dyeing operation in which phenylphenol is useful as a carrier but is particularly strong in the dyeing of synthetic ester fibers such as poly(ethylene. terephthalate). These are commonly dyed with acetate-type dyes, though the beneficial effect of the Dowfax is obtained with other types of dyes with which phenylphenol is useful as a carrier.

The practice of the invention is illustrated by the following examples.

Example 1.-Preparation of dye carrier oncentrate The concentrate was prepared by placing 44.4 grams of 45% aqueous Dowfax 2A1 solution (20 grams of active Dowfax 2A1) in a beaker and the o-phenylphenol added with stirring. The solution was heated to dissolve the phenol and cooled to room temperature to make sure there was no separation. 7.4 grams of o-phenylphenol was added in this way to give a clear concentrate.

Example 2.Use of concentrate in dyeing The dyeing was carried out using the procedure in Coloring of Postwar Synthetic Fibers by National Aniline Company. All weights are based on the weight of the cloth and a 30:1 bath factor (30 wts. of water per 1 wt. of cloth) was used at all times. Five 5" x 5" Dacron cloth patches (about grams) were scoured with water containing a surfactant for minutes at 160 F. The cloth was removed and rinsed well. The dye bath was 2,991,145. Patented July 4, 1961 prepared by filling a vessel with water to "A: the total volume and adding in succession 4% of the Dowfax 2A1 and o-phenylphenol concentrate, 6% monosodium phosphate and 2% Eastman Fast Yellow (an acetate type dye) which had previously been dispersed in a small amount of water. Water was added to bring the volume to the previously determined level, the cloth was put in at 110 F. and the bath was boiled for 90 minutes. The cloth was then removed, rinsed in clear water and treated 10 minutes at 180 F. in a 9% NaOHsolution to remove the phenol. The cloth was again rinsed, scoured, again rinsed, and then dried and ironed.

Example 3.C0mparative test Bath and procedure were the same except instead of 4% of the concentrate as in Example 2, the bath was charged with 1% sodium dodecylbenzene sulfonate and 3% of the Na salt of o-phenylphenol, the latter having previously been dissolved in 1.5% NaOH. The bath apeared to be completely in solution.

Comparing the dyed cloth from Examples 2 and 3 showed the color at 2 to be the more intense, indicating a more complete utilization of the dye.

In preparing the dye carrier concentrate the ratio of Dowfax to phenylphenol is suitably about 2 to 4 parts, by weight of Dowfax per part of phenylphenol. The percentage of water in the concentrate is not critical so long as enough is used to obtain a uniform solution or dispersion of the phenylphenol in the concentrate. This ordinarily requires about 40-50%, by weight, based on the entire concentrate. More may be used if desired, of course.

The amount of the concentrate used in the dye bath is not critical. As little as 1% produces a definite beneficial effect while further benefit may be obtained by use of larger amounts up to 5% or more. The choice of amount is essentially an economic one; i.e., one uses as much as the improved result justifies. This will vary somewhat with the particular dye and fabric being used.

While o-phenylphenol is the most widely used phenolic dye carrier, other phenols, particularly p-phenylphenol, are sometimes used. The use of Dowfax with these other phenols results in improved dyeing in the same way as when o-phenylphenol is used.

I claim:

1. In a dyeing process wherein a fabric to be dyed is immersed in a dye bath comprising, as a dye carrier, phenylphenol, the improvement comprising incorporating into said bath about 2 to 4 parts, by weight, of sodium References Cited in the-file of this patent UNITED STATES PATENTS 2,081,876 Prahl May 25, 1937 2,854,477 Steinhauer Sept. 30, 1958 2,926,987 Freyermuth et a1. Mar. 1, 1960 FOREIGN PATENTS 526,913 Canada June 26, 1956 

1. IN A DYEING PROCESS WHEREIN A FABRIC TO BE DYED IS IMMERSED IN A DYE BATH COMPRISING, AS A DYE CARRIER, PHENYLPHENOL, THE IMPROVEMENT COMPRISING INCORPORATING INTO SAID BATH ABOUT 2 TO 4 PARTS, BY WEIGHT, OF SODIUM DODECYLDIPHENYL OXIDE DISULFONATE PER PART OF PHENYLPHENOL THEREIN. 